Piston for internal-combustion motors



L. P. MOOERS.

PISTON FOR INTERNAL COMBUSTION MOTORS.

APPLICATION FILED JUNE28, 1916. RENEWED JUNE 21. 1920. 1,402,308.

Patented Jan. 3, 1922.,

2 SHEETS-SHEET I.

"NIH" Hlllll ll lll Patented Jan. 3, 1922.,

' 2 SHEETS-SHEET 2.

UNH 'TAlf FATE LOUIS P. MOOERS, 0F CINCINNATI, OHIO, ASSIGNOR, BY DTRECTAND MENTS, TO THE CLEVELAND TRUST COMPANY, OF CLEVMA.

RATION OF OHIO.

NT @FFHCE.

MESNE ASSIGN- OHIO, A Conro- PISTON FOR INTERNAL-COMBUSTION MOTORS.

releases.

Specification of Letters Patent.

Application filed .Tune 28, 1916, Serial No. 106,503. Renewed Tune 21,1920. Serial No. 390,623.

To all who in it may concem:

Be it known that I, LOUIS P. 'Moonns, a

citizen of the United States, residing at Cincinnati, in the county ofHamilton and State of Ohio, have invented certain new and usefulImprovements in and Relating to Pistons for Internal-Combustion Motors,of which the following is a specification.

This invention relates to pistons for use particularly in internalcombustion motors.

One of-the objects of my invention is to produce a simple, light,durable and efficient skirted piston peculiarly adapted to meet theconditions which exist within an internal combustion motor cylinder,including the stresses and strains imposed upon the piston, principallyduring the explosion stroke and by the high heat generated at this time,which heat must be efficiently and economically (a) utilized in thetranslalation of heat into mechanical energy and (b) that nottranslated, into mechanical energy properly dissipated.-

y present invention comprises improvements on the joint invention ofEdward O. Spillman and myself, disclosed in Letters Patent of the UnitedStates No. 1,092,870. It contemplates simplifying the construction andmanufacture of pistons of this patented type by making them in two ormore parts,

if desired of different materials, and of con-' siderably lightening theconstruction as compared with the integral cast structure Purely for thepurposes -of disclosure herein I have selected to illustrate anddescribe one construction of internal combustion motor, skirted pistonand a modification thereof embodying my improvements In the drawings,Fig. 1 is a side eleva-.

tion of a piston embodying my improvements.

2 is a section on the line 2-2, F ig. 1. Fig. 3 is a section on the line33, Fig. 2. Fig. 4 is a bottom plan View.

1 is the skirt, body or guide portion of the piston, which may be madeof a section of'steel tubing or a steel stamping, having diametricallyopposed apertures through it, 1*, 1 concentric, with the axis ofthewrist pin bosses, to permit the insertion and withdrawal of the wristpin, in the well known manner, as desired. The section 1 may be inderwalls with which it is adapted to coact and co-operate, that it shouldnot be necessary to machine this section or guide portion of the piston,understood that if desired it may be machined or treated in anypreferred mechanical manner.

3 indicates as an entirety a combined top or piston head and connector.It comprises an end wall 3, an outer peripheral wall 3 formed preferablywith suitable piston ring grooves 3 and a downwardly or inwardlyextending annular: section 3. section 3 is expanded at its lower end tohave a tubular section 3, the outer wall of which engages with the innerwall of the skirt 1 near the bottom of the latter. Intermediate its endsthe section 3 is preferably formed with dimetrically opposed alignedannular wrist pin bosses 3,3 one of which may have a downwardly orinwardly extending lug 3 formed with a screw-threaded opening to receivein the'well known manner a suitable locking bolt or screw for the wristpin. The periphery of the section 3 may be recessed, as indicated, at 3to provide drainage ducts for the lubricant which may collect betweenthe skirt 1 and the lower end may be made'unusually light, durable andefficient by having. the skirt 1 a section of steel tubing and thecombined head and connector a casting of metallic alloy havingrelatively low specific gravity, such for example as a suitable aluminumalloy. Furthermore. the casting for the part 3 may be not only ofmetallic alloy having relatively low-specific gravity, but alsopossessing a high coefficient -of heat conductivity, in which instancethe heat necessarily dissipated by the piston will be efiicientlydissipated by the web or tie piece 3 so as to insure that the skirt 1will be maintained at a relatively low temperature under all normalworking conditions.

Patented Jan. 3, 1922- although it will be This annular Where thecasting for the combined head and tie piece 3 is made of a metallicalloy having a relatively low specific gravity and high coefiicient ofheat conductivity, such as an aluminum alloy, the connection between itslower end 3 and the adjacent wall of the skirt 1 may be made in anysuitable mechanical manner, as for example by rivets 4, counter-sunk inthe sleeve 1, as indicated in dotted lines in Figs. 2 and 4.

It will be understood that the sleeve or skirt 1 may be constructed soas snugly to fit the inner walls of the motor cylinder, whereas the head3' may be given a considerable amount of clearance between its outerperiphery and the inner wall of the cylinder to allow for all necessaryexpansion of the head due to the high temperatures to which it issubjected. The heat-absorbed by the head is transferred downwardly bythe connecting piece 3 to the lower end of the skirt 1, and much of itis dissipated by radiation, so that the skirt is kept relatively cooland may be readily lubricated to provide and maintain the proper workingrelationship between it and the inner wall of the motor cylinder withwhich it co-acts. The fit between the skirt and the inner wall of thecylinder, as before indicated, may be a snug sliding fit, and the areaof the skirt which co-acts with the inner wall of the motor cylinder issuch as to insure against slapping or rapping of the piston against theinner wall of the cylinder. In fact, objectionable so-called pistonslap, incident to the operation of numerous types of pistons for use ininternal combustion motors, substantially is eliminated by the use ofapiston constructed in accordance with my invention. Furthermore, apiston embodying my improvements herein described practically eliminatesso-called oil pumping or transfer of an undue amount of oil or lubricantfrom the crank case to the upper end of the piston, resulting inundesirable smoking and undue and troublesome carbonization, among otherthings.

Due to the fact that the sleeve or skirt is maintained relatively coolunder all normal working conditions, the possibilities of scoring of theinner walls of the cylinder are practically eliminated.

The upper end of the skirt 1 is separated from the head 3 by an air gap.The presence of this air gap or air space between the upper edge of theskirt or body section .1 and the lower edge of the peripheral portion 3of the piston head, insures that the heat absorbed by the piston headprincipally will be transmitted inwardly and downwardly so that suchportion of it as does reach the skirt or body by convection will do soat the lower end of the skirt and will not be suflicient in amount tocause the necessary expansion of the skirt to effect binding between theskirt and inner wall of the cylinder or scoring. It will be understoodthat my invention contemplates any sort of a separated relationshipbetween the upper end of the skirt and the adjacent head 3 because ofwhich heat will not be transmitted efficiently or readily from said headto the skirt. It will be understood that this relationship might be thateven of apoor mechanical fit plr joint which would be a poor conductorof eat.

It will be noted that my composite piston may be made relatively lightin weight, which is of material advantage in assisting in reducing theweight of the reciprocating parts of the motor.

Pistons of my improved construction will be found to operatecompartively noiselessly, smoothly and efficiently within the cylindersof internal combustion motors.

To those skilled in the art, many modifications of and widely differingembodiments and applications of my invention will suggest themselves,without departing from the spirit and scope thereof. My disclosures andthe descriptions herein are purely illustrative and are not intended tobe in any sense limiting.

What I claim is:

1. A composite piston for an internal combustion motor, comprising ahead having an annular, grooved, piston r ng carrying flange and aconnector extendlng downwardly from said head and provided intermediateits ends with aligned wrist pin bosses, said head and connector belngcast integrally of an aluminum alloy, and a sheet iron guide sectioninto which said connector extends and to the lower end of which thelower end of said connector is secured, there being a relatively smallair gap between the upper end of said guide section and the adjacentedge of said head.

2. A composite piston for an nternal combustion motor, comprising a headexternally grooved to carry piston rings and a connector extendingdownwardly from said head and having formed intermediate its ends a pairof aligned wrist pin bosses, said head and connector being castintegrally of a metallic alloy having a lower specific gravity thaniron, and a sheet iron guide section into which said connector extendsand to the lower end of which the lower end of said connector issecured, there being a relatively small air gap between the upper end ofsaid guide section and the adjacent edge of said head. I

3. A composite piston for an mternal combustion motor, comprising ahead, wrist pin bosses, a web between said head and bosses and anextension below sald bosses cast integrally, and a separately formedwear-resisting guide section shaped snugly to fit the inner walls of themotor cylinder walls of the motor cylinder and secured to said extensionof said casting below the wrist pin bosses therein.

5. A .composite piston for an internal combustion motor, comprising ahead, wrist pin bosses, a web between said head and bosses and anextension below said bosses cast integrally of 'a metallic alloy havinga lower specific gravity than iron, and a guide section of ironconnected below said wrist pin bosses to said extension on the castingand having its upper edge separated from the adjacent wall of the headby a relatively poor heat conducting air gap.

6. A composite piston for an internal combustion motor, comprising ahead, wrist pin bosses, a web between said head and bosses and anextension below said bosses cast integrally of a metallic alloy having alower specific gravity than iron, and a sheet metal guide sectionsecured below said wrist pin bosses to said extension on the casting andhaving its upper edge separated from the adjacent wall of the head by anair gap.

7. A composite piston for an internal combustion motor, comprising ahead, aligned wrist pin bosses, a connecting web between the head andthe bosses and an annular extension below the bosses cast integrally ofa metallic alloy having relatively low specific gravity and shaped tofit relatively loosely within the inner walls of the motor cylinder, andan iron wear-resisting guide section adapted snugly to fit the innerwalls of the motor cylinder and'secure'd to said annular extensionbeneath said wrist pin bosses.

8. A piston comprising a head member, having an active end and anaxially extended portion of smaller diameter than the active end. andextended to a distance therefrom; and a skirted cross head member formedindependently of the head member and comprising a skirt portionoverlying the axially extended smaller portion of the head portion, andradially distanced therefrom, and means for attaching said cross headmember to the head member at a point distant from the active end of thehead portion. 9. A piston comprising a head section having an active endand an axially extended portion of smaller diameter than the active endand extended to a distance therefrom, said axially extended portioncarrying means for receiving a-wrist pin; a skirted cross head memberformed independently of the head member and comprising a skirt portionoverlying the axially extended smaller portion of the head member andpin receiving portion; and means for attaching said cross head member tothe head member at a point distant from the active end of the headportion.

10. A composite piston for an internal combustion motor, comprising ahead member, wrist pin bosses, means connecting said head member andwrist pin bosses and an extension below said bosses cast integrally of ametallic alloy having a lower specific gravity and higher coeflicient ofheat conductivity than iron, and a wear resisting guide section formedof a metal having a greater degree of hardness than said head connectedto said casting and having its upper edge separated from. said head by arelatively poor heat conducting air gap and its lower edge disposed at apoint below said wrist pin bosses.

11. A piston comprising a head member having an active end, alignedwrist pin bosses and connections between said head and wrist pin bossescast integrally, a guide portion formed independently of said castingand comprising wear resisting surfaces adapted in normal operation toengage the walls of the engine cylinder, and means for attaching saidguide portion to said casting at a point distant from the active end ofthe head member.

12. A piston for internal combustion engines formed in two parts, one ofwhich is made of metallic alloy having a lower specific gravity andhigher coeflicient of heat conductivity than iron and comprises a headportion, wrist pin bosses and an extens on beneath said bosses, and theother of which parts is made of a metal of greater degree of hardnessand greater wear resisting characteristics for rubbing contact with thecylinder walls than said first described part, and means for attachingsaid parts together at a point distant from the active end of the headportion.

13. A composite piston for an internal combustion motor, comprising ahead, wrist pin bosses and connecting parts between said head and bossescast integrally of a metallic alloy having a lower specific gravitythanriron, and a guide section of iron attached to said connecting partsand having its upper edge parts separated from the ad acent wall of thehead by an air gap.

14:. A composite piston for an internal combustion motor, comprising ahead, wrist pin bosses and connecting parts between said head and bossescast integrally of a metallic alloy having a low specific gravity incomparison with iron, and a cylinder ductin air gap provided between theupper part 0 the guide section and the lower part of the head.

15. A composite piston for an internal 5 combustion engine comprising ahead, wrist pin bosses and connections between said head and bosses castintegrally of a metallic alloy having a lower specific gravity andhigher coeflicient of heat conductivity than 10 iron, and a guidesection of iron connected

